.bk-root {
  .bk-logo {
    margin: 5px;
    position: relative;
    display: block;
    background-repeat: no-repeat;
    &.bk-grey {
      filter: url("data:image/svg+xml;utf8,<svg xmlns=\'http://www.w3.org/2000/svg\'><filter id=\'grayscale\'><feColorMatrix type=\'matrix\' values=\'0.3333 0.3333 0.3333 0 0 0.3333 0.3333 0.3333 0 0 0.3333 0.3333 0.3333 0 0 0 0 0 1 0\'/></filter></svg>#grayscale"); /* Firefox 10+, Firefox on Android */
      filter: gray; /* IE6-9 */
      -webkit-filter: grayscale(100%); /* Chrome 19+, Safari 6+, Safari 6+ iOS */
    }
  }

  .bk-logo-small {
    width: 20px;
    height: 20px;
    background-image: url();
  }

  .bk-logo-notebook {
    display: inline-block;
    vertical-align: middle;
    margin-right: 5px;
  }
}
